1. Field of the Invention
The present invention is related to an image processing apparatus in which vector data and bit map data, both of which are represented in multi-gradation, are inputted.
2. Description of the Related Art
Very recently, an image containing the vector data and the bit map data is represented in color modes and multi-gradation, so that the image data amount is considerably increased. On the other hand, the very high-speed image processing requirements are made with respect to the image processing apparatus for this image. More specifically, as to an image output machine such as a printer, there are two limitations. That is, such image data is required to be stored in a memory having a limited small storage capacity, and the stored image data is required to be printed in a high speed.
Conventionally, the vector data and the bit map data are stored in the memory having the limited small storage capacity, so that these data are stored in the memory using the description language to perform the image drawing operation of the description language data when the image data is outputted. Thereby, the image output process operation may be carried out using the small memory capacity.
Referring now to FIGS. 39-41, a description will be made of a conventional image processing apparatus for executing the memory storage by the description language.
FIG. 39 is a block diagram of the conventional image processing apparatus 40 for executing the memory storage by the description language. First, vector data and bit map data are inputted into a description language converting unit 41 to be converted into the description language which the conventional image processing apparatus 40 has. FIG. 40 is a block diagram of the conventional description language converting unit 41 by the description language. In the description language converting unit 41, the bit map data is converted into a bit map format having the description language by a bit-map-portion bit map converting means 45, whereas the vector data is converted into a vector format having the description language by a vector data converting unit 44. FIG. 41 is a block diagram of the vector data converting unit 44 of the conventional image processing apparatus by the description language. The vector data inputted into the vector data converting unit 44 is converted by a data analyzing unit 46 into the combination of the description language of vectors owned by the conventional image processing apparatus 40. The image processing apparatus 40 has three description language formats (straight line, rectangular shape and bit map). The straight line, the rectangular shape and the bit map are generated by a straight line converting unit 47, a rectangular shape converting unit 48 and a vector-portion bit map converting unit 49, respectively. For example, the vector data of a circular shape is converted into the combination of the straight lines by the straight line converting unit 47 being selected in the data analyzing unit 46. The vector data of a character is converted into a bit map by the vector-portion bit map converting unit 49 is selected in the data analyzing unit 46. The vector data of a widened straight line is converted into a rectangular shape vector by the rectangular shape converting unit 48 being selected in the data analyzing means 46. These converted data are outputted as description language data. The description language data produced in the above described manner are stored in a memory by the description language storage unit 42 shown in FIG. 39. When the image data is required to be outputted, a description language expanding unit 43 performs the analysis of the description language, the bit map conversions of all of the description language data, and the overlapping process operation based on the vector data attached to the description language and also the overlapping information owned by the bit map data input. As a result, the description language expanding unit 43 outputs the image data as the bit map data.
However, in case the data amount of the description language data stored in the memory by the description language storage unit 42 is increased and the number of the data overlapping operations is increased, lengthy time would be required for a time period during which the image data output is commenced and then is accomplished. As a result, there is a problem that when the high speed output engine is employed in a real time operable electronic appliance such as a laser printer, the image data can not be expanded just in time.
The present invention is to realize such an image processing apparatus capable of storing both vector data and bit map data in a storage device having a small data storage capacity without deteriorating the inherent characteristics of the vector data and bit map data, and also capable of outputting an image in a high speed by executing an overlapping process operation only one time when image data is expanded.